Mishkat al-Masabih 29 Excellent Qualities and Description of the Prophet كتاب الفضائل والشمائل 98

وَعَنْ أَنَسٍ قَالَ: تَوَفَّاهُ اللَّهُ على رَأس سِتِّينَ سنة. مُتَّفق عَلَيْهِ

Anas said God took him when he was just sixty years old. (Bukhari and Muslim.)